TOOTHED WHALES that Is to say, it is long and not very high. The skull is most like that of Balaena,, but the process of the frontal arching over the eye is broader relatively than in Bcdaena, and thus approaches JSalaenoptera. Nothing is known of the viscera of this "Whale. The whalebone is white, and the animal was first described by Dr. Gray from pieces of " "bone." It is not always that so fortunate a diagnosis of specific or generic difference has been made from a structure which apparently offers so little aid for discrimination, There is but a single species of the genus which is named J^eobala&na marc/inata,.1 SUB-ORDER 2. ODONTOOETL The Odontoceti have teeth but no whalebone; the blow-hole is single; the skull is not symmetrical; some of the ribs are two-headed. Fam. 1. Physeteridae.—This family of the Odontocetes may be thus denned:—All or most of the cervical vertebrae are fused together. The costal cartilages are not ossified. In the skull the pterygoids are thick and meet in the middle line ; the syra- physis of the mandible is long. Teeth, more or fewer, are found in both jaws, but those of the mandible are alone functional (? exc. JToffia). The pectoral limb is smallish. The throat is grooved by two or four furrows. This family of Whales is again susceptible of division into the two sub-families—Physeterinae or Sperm Whales and the £iphiinae or Beaked Whales. Professor P. J. van Beneden was strongly against any subdivision of what is here regarded as a perfectly natural family, embracing the Physeters and the Beaked Whales. There are, however, some reasons for the subdivision. The Ziphiinae have a reduced series of teeth, never exceeding two on each mandible, which contrasts with the fully-toothed mandibles of both Physeter and Kogia,* The stomach of the Ziphioids is extraordinarily complicated even for a Cetacean. The small bead of the 1atter group, which recalls in a curious way that of Mosasauroid reptiles and some Dinosaurs, is in contrast to the 1 For osteology see Hector, Trans, New Zeal. 2nst. vii.,1876, p. 251; and Bed&tid, 'Trans. Zo&l. Soc. xv. 1901, jx 87.